The video quality is so bad though that you probably couldn't tell the difference even if I recorded the same footage using the normal composite output. Maybe some day I'll buy a real camera, or some VGA capture thing.

This's the most exciting thing ever. I will happily throw hundreds of dollars to you to get a version that fits inside an av famicom and gives me ideally rgb / s-video so I can just wire it into the multi av port.

I saw you'd commented on youtube that you have no plans or progress with this project, is there any chance you might eventually come back to it, for a self contained version you can sell?

Yes, definitely. I just don't have time or interest to work on this right now. As I've said before, getting it out there requires a lot of work, some on areas I'm not too familiar with (e.g. I've never done a custom PCB).

Yes, definitely. I just don't have time or interest to work on this right now. As I've said before, getting it out there requires a lot of work, some on areas I'm not too familiar with (e.g. I've never done a custom PCB).

Have you thought about teaming up with someone who does have experience, like Krikzz, HardWareMan, Toodles or invzim? Seeing as this thread basically contains the full technical description of what you're doing, if you wait long enough someone else is just going to implement their own RGB hack based on your discovery, without cutting you in on the profits.

Yes, definitely. I just don't have time or interest to work on this right now. As I've said before, getting it out there requires a lot of work, some on areas I'm not too familiar with (e.g. I've never done a custom PCB).

Have you thought about teaming up with someone who does have experience, like Krikzz, HardWareMan, Toodles or invzim? Seeing as this thread basically contains the full technical description of what you're doing, if you wait long enough someone else is just going to implement their own RGB hack based on your discovery, without cutting you in on the profits.

Yeah I've thought about it briefly. If any of the fellas mentioned there want to partner up, feel free to PM me, although I won't have much time to work on this during the summer.

This is sort of a tangent, but I figured I'd share:On some level, the only hard part is intercepting the writes to the PPU; the rest is just a look-up-table. So I started coming up other ideas for what one might do with spare fuses in the FPGA. Since you're entirely wrapping the CPU side of the PPU anyway, if you considered adding some extended functionality, you'd want to make that availability detectable by the CPU.

So, here's a list, with "CPU side interceptions" first:

Add read-only ID register to some currently write-only register to detect presence of extended functions

These are view-only: writeable palette; blank top, bottom, and right side without affecting sprite 0; upscaling; change blanking color.

This can be done by postprocessing the crystal, and it won't be program-visible if fed to both the CPU and PPU clock inputs: Skip one period of the CLK input by one master clock at the start of each scanline and by four master clocks near the start of every second line 0. This would cause M2 to deviate slightly from 1.79 MHz, confusing some reset detection circuits, so space the skipped periods a bit apart throughout the first line.

These can in theory be implemented on a Game Pak that intercepts the entire CPU and PPU bus: dual-ported VRAM (already present in MMC5 ExRAM); steering of $4014 DMA to VRAM.

Only one is impossible on an NES and affects program-visible behavior: swap 2000/2001.

If you add any extras, it's no longer a NES. Except for the masking ones and other view-only effects, those seem okay.

The point is, you're already adding new hardware. As long as the incompatibilities won't be accidentally triggered, who cares? That's the entire point behind adding the signature. Code can detect what's available and use it if it wants. I admit the second list is fairly pipedreamy, but the only one in the first list that's not largely invisible or usable for Vs. System compatibility is hijacking DMA.

A nice addition—although I'm not altogether certain how to do it—would be a modification to the PAL NES to act more like a Dendy. (Fixing the 2A07's ÷16 is doable, but awkward, once you can inject a different clock frequency. Use an extra crystal or a PLL to make a CPU clock of ~28.4MHz. There's also the problem where vblank doesn't apparently last the whole 70 lines)

Most other things are either view-only (clipping) or for 2C04 and 2C05 support (missing pixel, rewriteable palette). Having that means the PowerPak can now play Vs. System games without any modification (modulo some of the dip switches necessarily reading back as 0; fixing that would require hardware on the expansion port).

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